I remember a comment about the possible effect of sandblasting to remove the paint before spraying a fresh coat, in terms of wheel balance thereafter.

 

Do you have references to cracked BBS on the STi? Not that I don't believe you, but there is way too much speculation and heresay on this topic.

 

I don't and its been awhile since I've been on the sites, but check out nasioc.com and iwsti.com

 

Sounds like a load of BS

i have powdercoated BBS rims and there fine...

unless u have cement Data stop starting stuff

and ur not a metalergist so get some cement facts then u can talk

 

i've never ONCE heard of somebody BREAKING or CRACKING their rims while powdercoating imo that'd be like asking if my rear view mirrors come off at high speeds...

 

Considering on a track day your brakes will get to 450F+++, Putting the wheel in a 380 deg oven shouldn't do any harm.....


When you heat up metal to that point, if anything it in most cases with most metals will make it stronger by realigning the particles to be stronger. I forget the word, my mom taught me this (she's a jeweler).

 

In theory it make sense to crack wheels if they get to hot, i guess its like glass is made from heat, but too much heat after will crack it.

But no i never heard of cracking due to powdercoating

 

THis is bs the metal wont get weak at these temps..
my father was a hi temp special metals engineer and he said thats the dumbest thing hes ever heard!!!

just a bunch of nonsence!

 

only crack kills... not powercoating hahaha

 

It is certainly not nonsense. It's a reality. I finally found the material curve for 6061-T6 aluminum yield and ultimate tensile strength. Nominally, the material has around a 39.5 ksi yield strength. At 387 degrees F for 1 hour, the material will now only have a 37.0 ksi or so yield strength. The ultimate strength has the same story - 45 nominally and 42 ksi after heating for 1 hour.

Bottom line is that I doubt the BBS engineers would design the rims to within almost 94% of material yield strength from the factory. I know at my company that this would not be an acceptable practice. I'll never be tracking these rims (except for autocross), so they should never reach yielding.

I'll be sending my rims to the powdercoater tomorrow. Case closed.

Note: If this sounds like a bunch of technical junk above, I apologize. I'm a nerd and overanalyze everything on my car.

 

I had my stock 8 wheels powdercoated glass black in a low temp. When doing a low temp powdercoating, you tend to have more of a orange peel look to them up close, but honestly it was hardly noticable. I think on the BBS's it wouldn't even be noticable simply cause the spoke are not flat faced.

I think the temp the guy used was 300 degrees.